Grinder regulator system



Jan. 16, 1923. 1,442,041..

c. A. BODDlE.

GRINDER REGULATOR SYSTEM.

FILED SEPT.H.1920. 2 SHEETS-SHEET I.

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WITNESSES: INVENTOR Clare/76a ,4 fiodd/e ATTORNEY Patented Jan. 16, 1923.

EI'LAREHTCE A. BODDZIE, 6F FITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTING- HG'USE ELECTRIC MANUFACTURING COMPANY,

A- CORPORATION OF PENNSYL- EEGULATQR SYSTEM.

To all whom it may concern:

Be it known that l, CLARENCE A. Bosnia, citizen of the United States, and a resident of Pittsburgh, in the county-oi Allegheny and State 0 Pennsylvania, have invented a useful improvement in Grinder ulator S tems, of which the following a specification.

i invention relates to regulator systems particularly, regulator systems for governing the operation of pulp grinders.

One object of my invention is to provide a pulp-grinder regulator system that shall maintain a substantially constant load on the grinder and that shall be provided with means, which is operated. in accordance with the chan e in load on the grinder, for preventing hunting action.

ln operating a pulp grinder, it is preferable to operate the grinder by an electric motor and to provide a hydraulic system vfor forcing the material to be ground into pulp against the face of the grinder. However, considerable trouble is experienced in such systems in so controlling the pressure of the hydraulic system as to maintain a constant load on the grinder and also be free from the so-called hunting action.

In a regulator system. constructed in accordance with my invention, the pulp grinder is preferably operated by a threephase motorand, a hydraulic system is provided for applying the load to the grinder. A regulator system, which is operated in accordance with the current supplied to the motor, is provided for governing the pressure in the hydraulic system to maintain a constant load on the grinder. Moreover, the setting of the regulator is changed in accordance with the variation of the hydraulic pressure to prevent hunting action.

The preferred form of practlcing my invention comprises a pulp grinder operated in any suitable manner by a three-phase motor. A load-applying device is hydraulically operated to force the material, to be ground into pulp, against the face of the grinder. A main valve is provided for con trolling the hydraulic pressure supplied to the load-applying device and an auxiliary valve is provided for controlling the main valve. A regulator, comprising an operating lever connected to the auxiliary valve and an electromagnet connected to the open winding 5 and inder 20. A valve 21,

Serial No. 409,71d.

ating lever, is provided for o auxiliary valve in accordance w. rent supplied to the motor.

A hydraulically-operated reactance device is provided for so changing the setting of the regulator as to prevent The reactance device comprises two connected pistons which operate within separate cylinders and whichv are connected together in any suitable manner. @ne of said cylinders is supplied with fluid pressure for operating the associated piston in accordance with the operation of the main valve. The second cylinder is supplied with fluid pressure for operating the associated piston in accordance with the operation of the auxiliary valve. The second cylinder is connected to the operating arm of the regulator for so changing the setting of the regulator as to prevent hunting action.

In the accompanying drawings, Fig. 1 is a diagrammatic view of a regulator system constructed in accordance with my invention, and Fig. 2 is a a modification of my invention.-

Referring to Fig. 1 of the drawings, a grinder l is connected to a three-phasemotor 2 in any suitable manner, as by. means of a shaft 3. The motor 2 comprises an armature winding 4 and a field-magnet is directly connected to a three-phase supply circuit comprising conductors 6, 7 and 8. A hydraulic system 9 is provided for applying the load to the grinder 1 and a regulator 10 is provided for governing the hydraulic system 9 in accordance with the current supplied to the motor 2.

The hydraulic system comprises a loadapplying device 11, a surge tank 12, a main valve 13 and an auxiliary valve 14. The load-applying device 11 comprises a piston head 15 which operates within a cylinder 16 for forcing the material 17 into engagement with the grinder 1. The piston head 15 is directly connected by a rod 18 to a second piston head 19 which operates Within a cylwhich operates within a pressure chest 22, is operated by a rod 23 and a lever 23 for controlling the application of hydraulic pressure to the piston head 19.

When the valve 21 is in the position hunting action. l

diagrammatic view of shown, hydraulic pressure is supplied to the cylinder 20 for forcing the material 17 into engagement with the grinder 1. Tn the reverse position .of the valve 21, hydraulic pressure is supplied to the cylinder 20 below the piston head to relieve the material 17 from any pressure tending to force it into engagement with the grinder 1. A system of pipes 24 is provided for connecting the pressure chest 22 with the surge tank 12. Two sprinklers 25, which are connected to the system of pipes 24, are provided for maintaining a spray upon the grinder 1.

' The main valve 13 comprises a main cylinder 26 having an inlet port 27, an exhaust port 28 and a port 29 which is connected to the surge tank 12 by a system of pipes 30. Two pistons 31 and 32, which are mounted on a rod 33, operate within the cylinder 26 and connect the port 29 with the inlet port 27 or with the exhaust port 28. The inlet port 27 is connected to any suitable source of hydraulic pressure.

The lower terminal of the rod 33 is provided with a piston 34 which operates within a cylinder 35 and the upper terminal of the rod 33 is provided with a piston 36 which operates within a cylinder 37. The cylinder 35 is directly connected to the auxiliary valve 14 by means of a pipe 38. The cylinder 35 is also connected, by a system of pipes 39, to a hydraulic device 40 for a purpose to be hereinafter set forth. The by draulic pressure supplied by the auxiliary valve 14 to the cylinder 35 controls the op eration of the main valve. The piston'36, operating within the cylinder 37, stabilizes the operation of the main valve.

The auxiliary valve 14 comprises a cylinder 41 having an inlet port 42, an exhaust port 43, and a port 44 which is connected to the cylinder 35 by the pipe 38. Two pistons 45 and 46, which are mounted on a rod 47, connect the port 44 either with the inlet port 42 or the exhaust port 43.

The regulator 10 comprises an operating lever 48, which is pivotally connected to the valve rod 47, and an electromagnet 49 which controls the operation of the lever 48 in accordance with .the current supplied to the motor 2. The electromagnet 49 comprises a coil 50, which is connected to the supply conductor 6 by means of a transformer 51, and a core armature 52, which is pivotally connected to the lever 48. A dash-pot 53 is provided for stabilizing the operation of the electromagnet 49 and a spring member 54 is connected to the lever 48 for supporting a portion of the weight of the core armature-52 and also for opposing the action of the electromagnet 49. The spring 54 exerts a force on the auxiliary valve tending to connect the port 44 to the inlet port 42, whereas the electromagnet 49 exerts 'a force tending to connect the port 44 to the exhaust port 43.

The hydraulic device 40 serves to exert a force reacting upon the regulator 10 in accordance with the operation of the main valve-and also in accordance with the operation of the auxiliary valve to prevent temporarily so-called hunting action. The hydraulic device 40 comprises a piston 55, which operates within a cylinder 56, and a second piston 57, which operates within a cylinder 58. The two pistons 55 and 57 are connected by means of a rod 59 and, a spring member 60 is disposed between one end of the cylinder 58 and the piston 55 for biasing the two pistons toward the left, as shown in the drawings. The cylinder 56 is connected to the system of pipes 30 between the main valve 13 and the surge tank 12, by

means of a system of pipes 61., One end of the cylinder 58'is connected to the cylinder 35 by the system of pipes 39, as heretofore set forth, and the opposite end of the cylinder 58 is connected by a system of pipes 62 to a cylinder 63.

l A piston 64, which is mounted upon a rod 65, operates within the cylinder 63.

The I'0d65 is pivotally connected to the I operating lever 48 of the regulator 10. Any suitable operating fluid is provided in the connection 62,between the cylinder 58 and the cylinder 63 in order to operate the piston 64 in accordance with the operation of the pistons 55 and '57. Two spring members 120 and 121 are connected to the lever 48' for biasing the lever to'a definite point.

If a load above normal value obtains upon the grinder 1, an abnormal current passes through the motor 2, and, accordingly, the energization of the electromagnet 49 is increased to operate the auxiliary valve 1.4. When the electromagnet 49 is energized to a predetermined degree, the lever arm 48 is given a movement of rotation on the end of the rod 65 to force the valve stem 47 downwardly and to connect the port 44 with the exhaust port 43. Thereupon, the fluid pressure below the piston 34 and within the cylinder 35 is reduced to move the rod 33 and the two pistons 31 and 32 downwardly, as shown upon the drawings. The port 29 is disconnected from the inlet port 27 and is connected to the exhaust port 28 in order to reduce the pressure on the hydraulic system 9 and, accordingly, to reduce the load on the grinder 1.

If no means were'provided for preventing hunting action, the load upon the grinder 1 would beconstantly decreased until the regulator 10 was operated by a normal value of current passing through the motor 1. However, the various moving parts would overtravel and cause the so-called hunting action. Accordingly, the hydraulic device 40 is provided for resetting the regulator 10 to prevent hunting action. The piston 57 within the cylinder 58 is operated in accord- .operation of the main valve 13.

ance with the operation of the auxiliary valve 14 and the piston 55 within the cylin der 56 is operated in accordance with the Consequently, the fluid pressure operating on each of the pistons 55 and 57 is reduced to effect a reduction in the fluid pressure operating on the piston 64. Accordingly, the setting of the regulator 10 is changed and the auxiliary valve 14 is operated to disconnect the port 44 from the exhaust port 43 just prior to the obtaining of normal load on the grinder 1.

If a load below normal value obtains upon the grinder 1, the value of the current supplied to the motor 1 is decreased and, accordingly, the energization of the coil 50 is decreased. Accordlngly, the spring member 54 overcomes the action of the electromagnet 49 and the valve rod 47 is raised to connect the port 44 with the inlet port 42. Fluid pressure is supplied to the cylinder and the main valve 13 is operated to connect the port 29 with the inlet port 27.

Thereupon. the fluid pressure supplied to the load-applying device 11 is increased to increase the load on the grinder 1.

- grinder 1 above normal value.

The hydraulic "device 40 anticipates the increased load on the grinder 1 and temporarily changes the setting of the regulator'10 to prevent increasing the load on the The cylinders 58 and 56 of the hydraulic device 40 a re supplied with increased fluid pressure in accordance with the operation of the auxiliary and the main valve. Consequently, increased fluid pressure is supplied-to the cylinder 63 and the piston 64 is subjected to a force tending to disconnect the port 44 from the inlet port 42. The auxiliary valve andalso the main valve are so operated just prior to the obtaining of normal load conditions upon the grinder '1 in such manner, as above set forth, as to prevent hunting action.

Referring to the system shown in Fig. 2

of the drawings, the auxiliary valve, which is shown in the system of Fig, 1, is replaced by an electric motor and the hydraulic devlce, which reacts uponthe regulator to' prevent hunting action, is actuated solely in accordance with the operation of the main valve. Like parts in the system shown in I Fig. 2 to those shown in Fig. 1 will be represented by corresponding reference char-v acters.

A main va1ve70 of the gate type is operated by an induction motor 71 for controlling the fluid pressure which is supplied to .the load-applying device 11. A regulator 72 is provided for operating the motor 71 in accordance with the current supplied to the motor 2' and, a hydraulic device 73 is operated in accordance with-the operation of the main valve for so changing the setting of the regulator 72 as to prevent hunting action. The main valve 70 comprises a gate 74 which is connected to a valve stem 75 and which is operated'within the valve chamber 76. The valve stem 75 is connected to the motor 71 by any suitable gearing system 77. 1

The motor 71 comprises a rotor 78 and a stator 79. The rotor 78 is mounted upon a shaft 80, which is not only associated with the gearing system 77, but is also associated with an electromagnetic brake 81. The brake 81 may be of any suitable construction for quickly stopping the motor when it is de-energized. In the system shown in the drawings, an electromagnet 82 is provided for releasing the brake whenever current is applied to the motor 71 and for permitting the instantaneous setting of the brake whenever themotor is de-energized. The motor is connected to the three-phase supply conductors 6, 7 and 8 by means of two switches 83 and 84.

The regulator 72 comprises a main con-- trol electromagnet 85, having an energizing coil 86, and a core armature 87. The core armature 87 is pivotally connected to a contact arm 88 and is also connected to a piston 89 which operates within a cylinder 90. The coil 86 is connected to .the supply conductor 6 in order to be energized in accordance with the current Supplied to the motor 2. The core armature 87 is operated by the piston 89in such manner as to prevent hunting action on the part of the regulator.

The contact arm 88 carries a contact member 91 which is adapted to engage stationary' contact members 92 and 93 according to the operation of the main magnet 85. A plurality of taps 94, 95 and 96 extend from the coil 86 of the main magnet 85' for a urpose to be hereinafter set forth.

he hydraulic device 73comprises a piston 94, which operatesfwithin a cylinder 95, and a piston 96 which operates within a cylinder 97. The two pistons 94 and 96 are connected by means of a rod 98. A spring member 99 is disposed between the cylinder 97 and the piston 94 for biasing the two pistons toward the left, as shown in the drawings. The cylinder 95 is connected to the hydraulic system intermediate the surge tank 12 and the main valve 70 in order to effect operation of the hydraulic device. 73 in accordance with the operation of the main valve."

'One end of the cylinder 97 is connected to the cylinder 90 below the piston 89 and theopposite end of the cylinder 97 is connected to the cylinder 90' above the piston 89. Thus, the piston 96, operating within the cylinder 97, supplies fluid pressure lto the cylinder 90 in accordance with the operation of the main valve '70. Such operation of the hydraulic device 73 changes the can:

setting of the regulator 72 to prevent hunting action. 6 I

The switch 83 comprises tin energizing coil 100, which is connected across the supply conductors 6 and 7 by engagement of the contact members 91 and 93, and a core armature 101 which is controlled by the coil 100. The switch members 102 and 103 and an interlock switch member 104 are connected to the core armature 101. The switch members 102 and 103 connect the mot0r 71 to the supply circuit in such manner as to operate the motor to close the main valve 70. The interlock switch member 104, upon operation of the switch 83,short-circuits that portion of the winding 86 which is included between the taps 95 and 96. Such operation ot the interlock switch member 104 changes the setting of the regulator to prevent hunting action.

The switch 84 comprises an energizing winding 105 which. is connected across the supply conductors 6 and 7, by"engagement of the main contact members 91 and 92. The coil 105 operates a core armature 106 which is directly connected to two switch members 107 and. 108 and an interlock switch member 109. The switch members 107 and 108 connect the motor 71 to the supply conductors 6, 7 and 8 in such manner as to effect an opening of the main valve 70. The interlock switch member 109, upon operation of the'switch 84c, opens-a short-circuit, which normally obtains across that portion of the winding 86 which is included between the taps 9t and 95, for changing the setting of the regulator 72 to prevent hunting action.-

Tt' a load above normal value obtains upon the grinder 1, an increased current is sup plied to the motor 2, and, accordingly, the

energization ot the main control magnet 85 israiscd above normal value. Accordingly, the magnet 85 operates the contact arm 88 to effect engagement between the contact members 91 and 93. Thereupon, the switch 83 is operated for so connecting the motor 71 to the supply circuit as to effect the closing of the valve 70. The closing of the valve decreases the fluid pressure supplied to the load-applying device 11 and, accord ingly, decreases the load upon the grinder 1.

It no means were provided for changing the setting oi the regulator 7 2 and for preventing hunting action, the load upon the grinder 1 would be steadily decreased until a normal value of current was supplied to the motor 2. Consequently, the regulator 7 2 would not be operated to prevent further decrease in the load upon the grinder 1 until the grinder was operated under normal load conditions and, the various moving parts would overtravel to reduce the load on the.

grinder 1 below normal value.

The hydraulic device '1' 3, which is operated in accordance with the operation of the main eeaoai valve 70, decreases the fluid pressure which The interlock switch member 104 short-cir cuits a portion of the coil 86 to decrease: the energization of the main magnet and, accordingly, to change the setting or the regulator. The. decreased energization of the electromagnct 85, which is caused by the interlock switch member 101 short-cir-cuiting that portion of the coil 86 which is included between the taps 95 and 96, tends to effect separation of the contact members 91 and 93 just prior to the obtaining of normal load conditions upon the grinder'l.

lit a load below normal value obtains upon the grinder 1, the energization of the main magnet 85 is reduced to eiiect engagement between the contact members 91 and 92. Thereupon, the switch 8 1 is operated for connecting the motor 71 to the supply circuit. The motor 71 is so operated as to sttect the opening of the valve 70 to increase the fluid pressure supplied to the load-applying device 11 and, acordingly, to increase the load upon the grinder 1.

The hydraulic device 73 is operated to supply an increased fluid pressure to the cylin dcr 90, tending to effect separation or the contact members 91 and 92. Moreover, the

interlock'switch member 109 opens a shortcircuit which normally obtains across that portion of the winding 86 which is included between the taps 94 and 95. Such operation of the interlock switch member 109 increases the energization of the electromagnet 85 to assist in effecting separation of the contact members 91 and 92. Accordingly, the setting of the regulator is changed and separation of the contact members 91 and 92 is efiected just prior to the obtaining of normal load conditions upon the grinder 1 to prevent any overtravel and the resulting hunting action. Although hunting action may be prevented by one of the means above set forth, it is preferable to have two means in order to stabilize the operation.

Modifications in the systems and in the arrangement and location of parts may be made within the spirit and scope of my invention, and such modifications are intended its comprising a egulator for varying the pressure in said hydraulic system to maintain a constant load on the grinder, and means for changing the settin of the regulator in accordance with the c ange in pressure in the hydraulic system to prevent hunting action.

2. In a grinder regulator system, the combination with a grinder, a motor for operating said grinder, and a hydraulic system for applying the load to said grinder, of a valve for controlling the hydraulic pressure ap plied to the grinder, means comprising a regulator for so governing the valve as to maintain a constant load on said grinder, and means for reacting upon said regulator in accordance with the hydraulic pressure applied to the grinder to prevent hunting action.

3. In a grinder regulator system, the combination with a grinder, and a hydraulic system for controlling the load on said grinder, of means comprising a regulator for controlling the pressure in said hydraulic system, and means for changing the setting of said regulator in accordance with the variation of pressure in said hydraulic system.

4. In a grinder regulator system, the combination with a grinder, and means for controlling the load on said grinder, of means comprising a regulator for governing said load controlling means, and means for changing the setting of said regulator in accordance with the variation of load on said grinder to prevent hunting action.

5. In a grinder regulator system, the combination with a grinder, and a hydraulic system for controlling the load on said grinder, of means comprising a regulator for controlling the pressure in said hydraulic system to maintain a constant load on said grinder, and hydraulic means for reacting on said regulator in accordance with the Va riation in pressure in the hydraulic system to prevent hunting action.

6. In a grinder regulator system, the combination with a grinder, an electric motor for operating said grinder, and a hydraulic system for applying the load to said grinder, of means comprising a regulator operatedin accordance with the current supplied to said motor for-governing the pressure in said hydraulic system to maintain a constant load on said grinder, and hydraulic means for reacting on said regulator in accordance with the variation in pressure in the hydraulic system to prevent hunting action.

In a grinder regulator system, the combination with a grinder, a hydraulic system for. applying the load to said grinder, and an electric motor for operating the grinder, of means comprising a regulator for governing the pressure of said hydraulic system in accordance with the current supplled to said motor, a piston operated in accordance with the variation of pressure in the hfdraulic system, and means controlled by said piston for changing the setting of said rag ulator to prevent hunting action.

8. In a grinder regulator system, the combination with a grinder, a hydraulic system for applying the load to said grinder, and an electric motor for operating the grinder, of a regulator operated in accordance with the current supplied to the motor, means comprising a valve controlled by said regulator for varying the pressure of said hydraulic system to maintain a constant load on the grinder, and means operated in accordance with the operation of said valve for reacting on said regulator to prevent hunting action. 9. In a grinder regulator system, the comhination with a grinder, a motor for operating said grinder, a hydraulic system for applying the load to said grinder, a main valve for controlling the hydraulic pressure applied to said grinder, and an auxiliary valve for controlling the main valve, of a regulator for controlling the auxiliary valve, in accordance with the electrical characteristics of said motor, and means for changing the setting of said regulator in accordance with the operation of the main and the auxiliary valves.

10. In a grinder regulator system, the combination with a grinder, and an electric motor for operating said grinder, of a hy draulic system for applying the load to said grinder, a main valve for varying the load on said grinder, an auxiliary valve for controlling the main valve, and a regulator for controlling. the auxiliary valve in accordance with the load on said motor, said regulator comprising means operated in accordance with the operation of the main and the auxiliary valves to prevent hunting action.

11. In a grinder regulator system, the combination with a grinder, an electric motor for operating said grinder, a hydraulic system for applying the load to said grinder. a main valve for varying the pressure of said hydraulic system, and an auxiliary valve for controlling said .main valve, of means comprising a regulator for operating said auxiliary valve in accordance with the current supplied to said motor, a hydraulic device having two pistons respectively operated in accordance with the operation of the main valve and of the auxiliary valve, and means controlled by said hydraulic device for changing the setting of the regulator to prevent hunting action.

12. In a regulator system, the combination with a grinder, means for operating said grinder, and a fluid-pressure system for applying load to said grinder, of means comprising a regulator for varying the pressure in said system to maintain a constantload on the grinder, and means co-operating with said regulator and operating in accordance with the change in pressure in said system to prevent hunting action.

13. In a regulator system, the combination with a grinder and a fluid-pressure sys tem for controlling the load on said grinder, of means comprising a regulator for controlling the pressure in said system, and

means co-operating with said regulator and operating in accordance With the variation of pressure in said system to prevent hunting action.

In testimony whereof I have hereunto subscribed my name this 8th day of September 1920.

CLARENCE A. BODDIE. 

